What is the ruling for a successor appointed after the Imam breaks purity during an incomplete prayer?
Chapter on Praying with Impurity and Other Matters
Al-Mughni
Book of Prayer
Primary text
It is permissible for a successor to be appointed for one who missed part of the prayer due to the Imam's impurity, and the successor should build upon whatever the Imam had completed (reading, bowing, or prostration) and make up the remainder after the congregation finishes. This position is attributed to 'Umar, 'Ali, and most who agreed with them on the permissibility of succession. If the followers finish before the Imam's appointed successor, they must sit and wait for him to complete the prayer and give the final salutation with them, as the followers waiting for the Imam is deemed more appropriate, drawing analogy from the waiting period in the Fear Prayer (Salat al-Khawf).
Supporting text
An alternative narration states the successor has the choice between building upon the previous part or starting anew. Malik stated that the successor should pray a complete prayer for himself, and when the followers finish, they should sit and wait for him to complete and give the salutation with them, prioritizing the followers' adherence to the Imam's authority over the successor's adherence to the followers. If the followers give the salutation without waiting, it is permissible.